1
linux/include/asm-sh/processor_64.h
Paul Mundt 9bbafce2ee sh: Fix occasional FPU register corruption under preempt.
Presently with preempt enabled there's the possibility to be preempted
after the TIF_USEDFPU test and the register save, leading to bogus
state post-__switch_to(). Use an explicit preempt_disable()/enable()
pair around unlazy_fpu()/clear_fpu() to avoid this. Follows the x86
change.

Reported-by: Takuo Koguchi <takuo.koguchi.sw@hitachi.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2008-03-26 19:02:47 +09:00

280 lines
6.5 KiB
C

#ifndef __ASM_SH_PROCESSOR_64_H
#define __ASM_SH_PROCESSOR_64_H
/*
* include/asm-sh/processor_64.h
*
* Copyright (C) 2000, 2001 Paolo Alberelli
* Copyright (C) 2003 Paul Mundt
* Copyright (C) 2004 Richard Curnow
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*/
#ifndef __ASSEMBLY__
#include <linux/compiler.h>
#include <asm/page.h>
#include <asm/types.h>
#include <asm/cache.h>
#include <asm/ptrace.h>
#include <asm/cpu/registers.h>
/*
* Default implementation of macro that returns current
* instruction pointer ("program counter").
*/
#define current_text_addr() ({ \
void *pc; \
unsigned long long __dummy = 0; \
__asm__("gettr tr0, %1\n\t" \
"pta 4, tr0\n\t" \
"gettr tr0, %0\n\t" \
"ptabs %1, tr0\n\t" \
:"=r" (pc), "=r" (__dummy) \
: "1" (__dummy)); \
pc; })
/*
* TLB information structure
*
* Defined for both I and D tlb, per-processor.
*/
struct tlb_info {
unsigned long long next;
unsigned long long first;
unsigned long long last;
unsigned int entries;
unsigned int step;
unsigned long flags;
};
struct sh_cpuinfo {
enum cpu_type type;
unsigned long loops_per_jiffy;
unsigned long asid_cache;
unsigned int cpu_clock, master_clock, bus_clock, module_clock;
/* Cache info */
struct cache_info icache;
struct cache_info dcache;
struct cache_info scache;
/* TLB info */
struct tlb_info itlb;
struct tlb_info dtlb;
unsigned long flags;
};
extern struct sh_cpuinfo cpu_data[];
#define boot_cpu_data cpu_data[0]
#define current_cpu_data cpu_data[smp_processor_id()]
#define raw_current_cpu_data cpu_data[raw_smp_processor_id()]
#endif
/*
* User space process size: 2GB - 4k.
*/
#define TASK_SIZE 0x7ffff000UL
#define STACK_TOP TASK_SIZE
#define STACK_TOP_MAX STACK_TOP
/* This decides where the kernel will search for a free chunk of vm
* space during mmap's.
*/
#define TASK_UNMAPPED_BASE (TASK_SIZE / 3)
/*
* Bit of SR register
*
* FD-bit:
* When it's set, it means the processor doesn't have right to use FPU,
* and it results exception when the floating operation is executed.
*
* IMASK-bit:
* Interrupt level mask
*
* STEP-bit:
* Single step bit
*
*/
#if defined(CONFIG_SH64_SR_WATCH)
#define SR_MMU 0x84000000
#else
#define SR_MMU 0x80000000
#endif
#define SR_IMASK 0x000000f0
#define SR_FD 0x00008000
#define SR_SSTEP 0x08000000
#ifndef __ASSEMBLY__
/*
* FPU structure and data : require 8-byte alignment as we need to access it
with fld.p, fst.p
*/
struct sh_fpu_hard_struct {
unsigned long fp_regs[64];
unsigned int fpscr;
/* long status; * software status information */
};
#if 0
/* Dummy fpu emulator */
struct sh_fpu_soft_struct {
unsigned long long fp_regs[32];
unsigned int fpscr;
unsigned char lookahead;
unsigned long entry_pc;
};
#endif
union sh_fpu_union {
struct sh_fpu_hard_struct hard;
/* 'hard' itself only produces 32 bit alignment, yet we need
to access it using 64 bit load/store as well. */
unsigned long long alignment_dummy;
};
struct thread_struct {
unsigned long sp;
unsigned long pc;
/* This stores the address of the pt_regs built during a context
switch, or of the register save area built for a kernel mode
exception. It is used for backtracing the stack of a sleeping task
or one that traps in kernel mode. */
struct pt_regs *kregs;
/* This stores the address of the pt_regs constructed on entry from
user mode. It is a fixed value over the lifetime of a process, or
NULL for a kernel thread. */
struct pt_regs *uregs;
unsigned long trap_no, error_code;
unsigned long address;
/* Hardware debugging registers may come here */
/* floating point info */
union sh_fpu_union fpu;
};
typedef struct {
unsigned long seg;
} mm_segment_t;
#define INIT_MMAP \
{ &init_mm, 0, 0, NULL, PAGE_SHARED, VM_READ | VM_WRITE | VM_EXEC, 1, NULL, NULL }
extern struct pt_regs fake_swapper_regs;
#define INIT_THREAD { \
.sp = sizeof(init_stack) + \
(long) &init_stack, \
.pc = 0, \
.kregs = &fake_swapper_regs, \
.uregs = NULL, \
.trap_no = 0, \
.error_code = 0, \
.address = 0, \
.fpu = { { { 0, } }, } \
}
/*
* Do necessary setup to start up a newly executed thread.
*/
#define SR_USER (SR_MMU | SR_FD)
#define start_thread(regs, new_pc, new_sp) \
set_fs(USER_DS); \
regs->sr = SR_USER; /* User mode. */ \
regs->pc = new_pc - 4; /* Compensate syscall exit */ \
regs->pc |= 1; /* Set SHmedia ! */ \
regs->regs[18] = 0; \
regs->regs[15] = new_sp
/* Forward declaration, a strange C thing */
struct task_struct;
struct mm_struct;
/* Free all resources held by a thread. */
extern void release_thread(struct task_struct *);
/*
* create a kernel thread without removing it from tasklists
*/
extern int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags);
/* Copy and release all segment info associated with a VM */
#define copy_segments(p, mm) do { } while (0)
#define release_segments(mm) do { } while (0)
#define forget_segments() do { } while (0)
#define prepare_to_copy(tsk) do { } while (0)
/*
* FPU lazy state save handling.
*/
static inline void disable_fpu(void)
{
unsigned long long __dummy;
/* Set FD flag in SR */
__asm__ __volatile__("getcon " __SR ", %0\n\t"
"or %0, %1, %0\n\t"
"putcon %0, " __SR "\n\t"
: "=&r" (__dummy)
: "r" (SR_FD));
}
static inline void enable_fpu(void)
{
unsigned long long __dummy;
/* Clear out FD flag in SR */
__asm__ __volatile__("getcon " __SR ", %0\n\t"
"and %0, %1, %0\n\t"
"putcon %0, " __SR "\n\t"
: "=&r" (__dummy)
: "r" (~SR_FD));
}
/* Round to nearest, no exceptions on inexact, overflow, underflow,
zero-divide, invalid. Configure option for whether to flush denorms to
zero, or except if a denorm is encountered. */
#if defined(CONFIG_SH64_FPU_DENORM_FLUSH)
#define FPSCR_INIT 0x00040000
#else
#define FPSCR_INIT 0x00000000
#endif
#ifdef CONFIG_SH_FPU
/* Initialise the FP state of a task */
void fpinit(struct sh_fpu_hard_struct *fpregs);
#else
#define fpinit(fpregs) do { } while (0)
#endif
extern struct task_struct *last_task_used_math;
/*
* Return saved PC of a blocked thread.
*/
#define thread_saved_pc(tsk) (tsk->thread.pc)
extern unsigned long get_wchan(struct task_struct *p);
#define KSTK_EIP(tsk) ((tsk)->thread.pc)
#define KSTK_ESP(tsk) ((tsk)->thread.sp)
#define cpu_relax() barrier()
#endif /* __ASSEMBLY__ */
#endif /* __ASM_SH_PROCESSOR_64_H */